Changes in libsoup from 3.7.3 to 3.8.0:

* Harden authentication:
    * Check `nonce` validity in Digest authentication (CVE-2026-3099) [Milan Crha]
    * Do not send cached proxy credentials after a redirect to a different origin [Milan Crha]
* Harden multipart handling:
    * Fix an out-of-bounds read when less data than the boundary is buffered (CVE-2026-66337) [Patrick Griffis]
    * Limit the length of part headers [Milan Crha]
    * Fix a leak of the current part's headers [Patrick Griffis]
* Prevent request smuggling in the server:
    * Close the connection after an early response to `Expect: 100-continue` [Patrick Griffis]
    * Reject `Host` headers containing URI delimiters [Patrick Griffis]
    * Require chunk-size to begin with a hex digit [Samuel Dainard]
* http2:
    * Fix skipping over multiple buffered chunks of a response body [Milan Crha]
    * Fix a `GCancellable` leak [Michael Catanzaro]
* Fix the build on platforms without `dlfcn.h` [Yegor Yefremov]
* Update Belarusian translation [Vasil Pupkin]
* Update Slovenian translation [Martin]